Chicken Pot Pie

A pie is excellent for a different Sunday Roast to up the comfort factor, and I can't tell you how many chicken pot pies I have cooked. That crisp puffy top encasing a world of deliciousness within. Using puff pastry, and I feel no shame in buying it, you get all sorts of luscious layers- from the bit that just touches the sauce, and goes all soggy and the golden, crisp top. It seems very difficult when you read through this recipe to think where on earth you could go wrong.
You don't need any extra starch with this, I just serve my cabbage, pine nut and parsley salad, with kale instead of cabbage today. All that is some steamed kale, toasted pine nuts, parsley leaves and some good oil drizzled over top.
1)Prepare 2 chopped leeks, make sure to score down the skin of the vegetable lengthways and clean out any soil. Slice it finely, and add it to a pan of hot vegetable oil. Add about 4 crushed cloves of garlic, some chopped mushrooms (I love chestnut ones) and cook them down. You will be amazed how much their volume decreases. Also add some pancetta cubes and let them cook (if you want them really crisp cook them first and allow their rendered fat to cook the vegetables).
2)Chop up some chicken, and yes, I'm using the much too fashionable breast for this, but I do so much prefer it to all the brown gristle of thighs. Don't have them too small, because a big hefty chunk of chicken is rather lovely. Add it to the pan and cook until it colours, then add about 1 tbsp dried thyme.
3)I know very much how unfashionable it is to add flour to thicken a sauce- you're all about egg yolks and cream or cornflour, but making a lazy roux to thicken the sauce until it more than coats the back of a spoon is really all I can tolerate. Add about 50g butter, melt it, then mix in about 2 tsp of mustard powder, white pepper and 2 tbsp plain flour. Mix in about 500ml hot chicken stock, and about a glass full of white vermouth or white wine (white is always preferred by me with chicken, which is why I prefer coq au riesling to coq au vin) and mix it in well. Add some frozen peas and some dried apricots snipped in and let it bubble for a bit until it tastes to your liking. Salt and more pepper may be necessary.
4)It's so important to let this whole filling cool completely before you contemplate putting buttery pastry on top, or the pastry will melt in the oven and you'll have a vile mess on your hands. When it is cool, pour into a pie pan, and cut a thin strip of pastry to line the rim of the dish, and press it down, then place the rest of the pre-rolled sheet on top. Press it down all around the rim, then cut away at the excess, but don't throw it away. You'll see. You can also press a fork round the rim, but that's pure for aesthetic value. Using a knife, prick about three holes through the lid.
5)This is optional, but I think it looks so beautiful if you use the excess to cut out some leaves or stars or something to adorn the lid. It doesn't have to be perfect, but I'm mainly saying that because I'm so proud of my effort I don't want your better attempt blurring mine. Beat an egg, and use it to wash all over the lid, and to make your pastry cuttings stick and bake at 180 for about 25 minutes, until the lid is golden and puffy and piping hot.